WO2007036297A1

WO2007036297A1 - Method for colouring toothbrush filaments

Info

Publication number: WO2007036297A1
Application number: PCT/EP2006/008841
Authority: WO
Inventors: Thorsten Emge
Original assignee: Braun Gmbh
Priority date: 2005-09-23
Filing date: 2006-09-12
Publication date: 2007-04-05
Also published as: EP1926411A1; DE102005045501A1; US20080256725A1; HK1120377A1; CN101272715B; CN101272715A

Abstract

The invention relates to a method for inserting a consumable, especially a wear indicator dye, into toothbrush filaments and/or other wearing parts used for personal care, whereby the consumable is introduced into a medium which is subjected to a pressure above atmospheric pressure, and the toothbrush filaments and/or the wearing part are exposed to a pressurised consumable medium mixture for a pre-determined impregnation time. The inventive method is characterised in that the medium into which the consumable is introduced contains CO2 as the essential component. Preferably, the consumable CO2 mixture circulates in a pressurised container under a high pressure, such that it infiltrates around the toothbrush filaments or the corresponding wearing part.

Description

Process for coloring toothbrush filaments

The present invention relates to a method of incorporating a wear indicator dye or other consumable consumable in use of the appliance in a similar manner, to toothbrush filaments and / or other consumables for personal use where the consumable is placed in a medium that is below superatmospheric Pressure is applied, and the toothbrush filaments and / or the consumable part are subjected to the pressurized consumable medium mixture for a predetermined exposure time.

In toothbrush bristles, it is known to use a wear indicator in the form of a coloring, which changes color with increasing use or wear. In this case, a dye is diffused into the outer layer of the monofilaments, which gradually volatilizes again through the use of the toothbrush, so that the toothbrush filaments gradually lose their coloring and return to their original color, whereby the user of the toothbrush recognize their wear condition can. It has been customary to introduce the wear indicator dye by a dipping process in the toothbrush filaments. US 4,802,255 and EP 0 303 202 B1 suggest in this regard to add a suitable food colorant, such as erythrosines, in an aqueous solution of a certain pH and then to boil the dye solution and add the filaments to the heated dye solution for 60 minutes diving. In order to achieve a greater penetration depth of the ink, it is proposed in the abovementioned publications that the dye solution with the filaments immersed therein be pressurized with superatmospheric pressure in a pressure vessel.

Although these known dipping methods for toothbrush filaments have been very successfully implemented on a large-scale industrial scale, they nonetheless have some problematic aspects. In particular, undesired influence of the filament properties can occur due to the high dyeing temperatures. In addition, they use acetic acid and require neutralization and intensive washing of the filaments after the dyeing process. Here, the present invention seeks to remedy this situation.

The present invention has for its object to provide an improved method for introducing a wear indicator dye or other consumable in toothbrush filaments or other wear parts of personal need, which avoids the disadvantages of the prior art and the latter in an advantageous manner further develops. In particular, lower process temperatures and a gentler treatment of the filaments are to be achieved and expensive post-treatment steps are avoided.

According to the invention, this object is achieved by a method according to claim 1. Preferred embodiments of the invention are the subject of the dependent claims.

According to the invention, it is therefore provided to introduce the consumable using CO ₂ under high pressure into the toothbrush filaments or the corresponding consumable part of the personal need. The medium into which the consumable to be introduced and which is placed under superatmospheric pressure contains CO ₂ at least as an essential ingredient. In particular, the medium may consist essentially completely of CO ₂ . The consumable is pressurized with CO ₂ to then add the toothbrush filaments into the resulting consumable CO ₂ mixture thereby introducing the consumable into the toothbrush filaments. If the toothbrush filaments are exposed to the high-pressure consumable CO ₂ mixture, the consumable can diffuse into the outer layers of the filaments.

Optionally, the consumable may first be dissolved in water before being added to the CO ₂ . In this case, the consumable according to an advantageous embodiment of the invention to 0.005% to 0.5%, preferably about 0.05% to 0.3%, be dissolved in water before the resulting solution is added under pressure with the CO ₂ , Alternatively, the consumables can also be added entirely without the addition of water with the CO ₂ , especially when using water-insoluble consumables.

Advantageously, the introduction of the consumable takes place without separation of the toothbrush filaments. In a further development of the invention, whole filament strands, so-called hanks, and / or filament spools are charged with the consumable CO ₂ mixture. Through the use of CO ₂ uniform coloration or incorporation of the consumable can be achieved even without separation of the filaments. It can be summarized in a strand of filaments, a so-called Hank, several 10,000 individual filaments to the strand. For toothbrushes filament strands of 1 m - 2m length and 30mm to 70mm diameter can be used consisting of about 30,000 to 80,000 individual filaments, which are acted upon introduction of the entire filament strand in the apparatus simultaneously with the consumable CO _Σ mixture. AI Alternatively, filaments can be dyed on spools on which several 10.00 μm filaments can be wound. Preferably, coils are used whose coil core and / or their flanges or their side walls are permeable, so that the consumable CO ₂ mixture can circulate through the walls of the bobbin.

The simultaneous treatment of a plurality of toothbrush filaments taken together to form a filament strand and / or wound onto a filament spool considerably simplifies the handling of the filaments during the process. In particular, the transport of the filaments is unnecessary in isolated form, which is very expensive in conventional methods.

In order to achieve a more uniform introduction of the consumable and a better penetration of the filament strands or the winding layers, according to an advantageous embodiment of the invention, the pressurized consumable CO ₂ mixture is caused to flow, so that the toothbrush filaments or the wearing part of the personal If necessary, the mixture is flowed around. In particular, the mixture may be circulated through a pressure vessel and / or a pipe system, so that the consumable particles mixed with CO _{2 are} repeatedly and repeatedly brought into contact with the filaments.

Advantageously, the toothbrush filaments or the corresponding wearing part, in which the consumable is to be introduced, are exposed to the mixture in a discontinuous process in a pressure vessel. Instead of a so-called batch process, it would also be conceivable to apply the consumable CO ₂ mixture to the filament strands or coils in a continuous or semi-continuous process. However, discontinuous process control achieves excellent dyeing or incorporation results with simpler equipment.

With regard to the process parameters in the application of the toothbrush filaments with the consumable C0 ₂ mixture various modifications and adjustments to the respective parts to be dyed are possible and useful.

A preferred embodiment of the invention may be that the medium containing the CO ₂ as an essential ingredient for introducing the consumable in the toothbrush filaments by suitable pressure and / or temperature in the - A -

supercritical state is brought. As a result, it is possible to achieve particularly uniform dyeings, even of strand and coil material, and high penetration depths.

With regard to the temperature, the present method is advantageously characterized by lower temperatures than the prior art. In principle, the method can be carried out already at room temperature, whereby virtually no impairment of the filaments to be treated is achieved. However, it can also be driven temperatures up to 140 ⁰ C. According to a preferred embodiment of the invention, the consumable-medium mixture, which is applied to the toothbrush filaments, preferably be brought to about 60 ⁰ C to 8O ⁰ C. These temperatures are significantly lower compared to conventional toothbrush filament dyeing methods, so that undesirable effects on filament properties can be avoided.

The pressures under which the consumable-medium mixture is maintained during the action on the toothbrush filaments or the corresponding consumable part may be between 5 bar and 300 bar, preferably with pressures between 60 bar and 200 bar. According to a particularly advantageous embodiment of the invention, pressures between 85 bar to 150 bar can be adjusted.

The exposure time can be between a few minutes and a few hours. Depending on the setting of the other process parameters, sufficient results with regard to quantity, penetration depth and uniformity of substance introduction can already be achieved with an exposure time of 40 to 80 minutes.

Preferably, the discontinuous introduction process is formed in two stages. After loading with the consumable C0 ₂ mixture, the toothbrush filaments or the corresponding consumable part of the personal need are removed from the corresponding pressure container and placed in a sink or a suitable winding apparatus to a short rinse, preferably from two to five minutes, make. In addition to the two dipping processes once in the consumable CO ₂ mixture and once in the rinsing liquid no further process steps such as neutralization, deposition removal, etc. are necessary.

In particular, the rinsing process is carried out as a pure water rinse, in which no acids or neutralizers are used. This will on the one hand a gentler On the other hand, the process is simplified in terms of safety and environmental aspects.

Appropriately, the consumable medium mixture is cooled after the expiration of the predetermined contact time and relaxed before the toothbrush filaments or the corresponding wearing part are removed.

The process parameters can be varied depending on the desired dyeing or Einbringgebnis. Advantageously, the temperature, the pressure and the exposure time for the application of the consumable C0 ₂ mixture can be determined such that a penetration depth or penetration depth of about 1% to 30%, preferably 5-25%, of the radius of the toothbrush filaments is reached from the outside.

A major application of the present method is the introduction of a wear indicator dye into the filaments of a toothbrush, which consumes again as the toothbrush is in use, thus indicating a corresponding color change of the toothbrush filaments in terms of their wear. In principle, different dyes can be introduced into the filaments. According to a preferred embodiment of the invention, the dye Indigotin FD & C Blue no. 2, CAS-No. 860-22-0, which is dissolved to 0.005% to 0.5% in water and CO _{2 is} added under pressure. As an alternative to the said dye can of course other colors, such. B. FD & C Red No. 3, FD & C Yellow No. 6 or FD & C Green No. 3, to be used.

Alternatively, water-insoluble dyes can be used, which then result in a permanent color. According to a preferred embodiment of the invention Indigo Carmine, Azure Blue, Tetra Blue, FD & C Blue No. 1, FD & C Blue No. 1 AI. Lake and phthalocyanine dyes such as Heliogen Blue B can be used.

In addition to the incorporation of dyes for the purpose of wear indication, however, other consumables, such as flavor, odor, and / or antibacterial agents and similar application materials that consume in use of the equipment, in the toothbrush filaments or the corresponding wear part of personal needs be introduced. For example, as flavorings and / or odors for food approved flavorings, such. As menthol, carvone, cinnamon or fruit flavors introduced. As antibacterial substances, silver ion-containing compounds, such as silver-zinc zeolites, such as IRGAGUARD types from Ciba, or the Sanitized types from Clariant, can be introduced into the toothbrush filaments or the corresponding wear part of personal need with the aid of the method according to the invention ,

Particularly advantageously, the method for the introduction of said substances in toothbrush filaments made of plastic is suitable. The toothbrush filaments which can be used in the present process are in particular monofilaments of polymers, such as. As polyamide or nylon. In particular, the filaments of PA6.6, PA6.10 and / or PA6.12 can be used. The filaments used are advantageously extruded plastic threads which are stretched and then fixed. Preferably, filaments for toothbrushes in a diameter range of 50 .mu.m to 500 .mu.m, in particular 100 .mu.m to 250 .mu.m, dyed.

However, the use of the method is not limited to toothbrush filaments. The consumables that consume when using the appropriate equipment can, with the method also in an advantageous manner in plastic moldings produced z. B. by injection, are introduced, whereby a temporary introduction of the respective substance is created, which is gradually eliminated by use. As a result, z. B. an indicator function can be achieved on the corresponding plastic molding. This is alternatively an off e.g. Thermoplastic elastomer produced, in particular soft-elastic cleaning element. According to an advantageous embodiment of the invention, such a plastic molded part can be used in the head area or on the handle of a toothbrush. However, other wear products of personal need can be coded by the present method with the corresponding consumable. In addition to so-called brush-ups or brush-aways, i. elastic finger toothbrushes, water filter replacement indicators, dental floss or replacement electric toothbrushes can be provided with the appropriate consumable by the present method.

These and other features and advantages of the invention, which are themselves, in combination and subcombination with each other subject of the invention and may constitute advantageous embodiments of the invention, except as apparent from the claims and from the following description of a preferred embodiment with reference to an accompanying drawing. In the drawing shows: 1 shows a schematic flow diagram of a two-stage, discontinuous dyeing process for toothbrush filaments on a spool.

In the embodiment shown in Fig. 1, toothbrush filaments 1 wound on a bobbin 2 are dyed with a wear indicator dye. On the spool 2 several 10,000m filament are wound, the coil 2 having a bobbin of permeable material. In particular, the flanges or side walls 3, so the sides of the coil and the coil core 4 are permeable to the dye.

The filaments 1 used here are plastic threads which are extruded, drawn and fixed from polyamide, in particular PA6.6, PA6.10 and / or PA6.12, having a diameter range from 50 .mu.m to 500 .mu.m. The filaments are preferably dyed without Avivage, but can also be dyed with such depending on the basis of the finish. A finish is a subsequent coating of the filaments to improve handling, which may be formed on a silicone or hydrocarbon basis.

In a pressure vessel 5, a dyeing liquor is circulated, which consists of the dye Indigotin FD & C Blue no. 2, CAS-No. 860-22-0, to 0.005% to 0.5% dissolved in water and CO ₂ , which is added to the dye solution under pressure. The pressure vessel 5 can circulate with a suitable pipe system 6 to the dye-CO ₂ mixture through the pressure vessel 5 and thus produce a forced flow in the pressure vessel.

If the dyeing liquor is filled into the pressure vessel 5, the pressure vessel 5 and the pipes 6 are heated to a desired temperature, so that the dyeing liquor also receives the desired temperature. Then, the lid of the pressure vessel 5 is opened and immersed the coil 2 with the filaments 1 in the dyeing liquor and fixed. The pressure vessel is closed and exposed to CO ₂ . Then, the circulation is started and dyed on reaching the intended dyeing temperature for a certain exposure time, cooled and then relaxed again. Thereafter, the filament spool 2 can be removed from the pressure vessel 5 and is freed in a water bath 7 with pure water of dye residues. As shown in FIG. 1, the container of the water bath 7 may have an inflow and an outflow, so that here too the water flows through the container.

Specifically, the pressure vessel 5 and the dye liquor received therein can be heated to a temperature between 60 ° C and 120 ⁰ C. The pressure is preferably between set 60 bar and 200 bar, the filaments 1 are treated on the spool 2 between 40 and 80 minutes in the pressure vessel 5. The rinsing process in the water bath 7 is carried out for preferably two to five minutes. Thereafter, the filaments 1 can be dried at room temperature. As a result of the circulation of CO ₂ in and / or through the pressure vessel 5, a uniform through-coloration of the filaments 1 wound on the bobbin 2 can be achieved. In this case, the dye diffuses into each individual filament from the outside, whereby the dye penetrates to different depths depending on the dyeing condition, so that different color intensities can be achieved. In order to obtain the desired indicator effect in the area of recommended toothbrush use, the penetration depth of the dye is preferably 1% to 30% of the radius of the outer of the individual filaments 1.

With the method according to the invention, considerable advantages over the prior art can be achieved:

Since no organic or inorganic acid (e.g., acetic acid) is needed, the process is simplified and the filaments are not damaged.

Neutralization or intensive washing of the filaments is not necessary. Nevertheless, there are no salt deposits on the filament surface.

Filament damage due to acid-induced swelling and shrinkage of the filament can be avoided.

By coloring entire Hanks or coils, the process can be considerably accelerated and the problematic handling of individual filaments can be avoided.

The processability of the filaments dyed by the process according to the invention in subsequent production steps of the toothbrush is improved, in particular the filaments can be better rounded at their tips.

Claims

claims

A method of incorporating a wear indicator dye into toothbrush filaments (1) and / or other consumables of dental care articles wherein a consumable is placed in a medium which is placed under superatmospheric pressure and wherein the toothbrush filaments (1) and / or the consumable part with the pressurized consumable medium mixture are applied for a predetermined exposure time, characterized in that the medium, in which the consumable is added, contains CO ₂ as an essential ingredient.

2. Method according to the preceding claim, wherein the medium consists of CO ₂ .

3. The method according to any one of the preceding claims, wherein the consumable is dissolved in water before it is added to the CO ₂ .

4. The method according to the preceding claim, wherein the consumable is dissolved to 0.005% to 0.5% in water.

5. The method according to any one of the preceding claims, wherein a plurality of toothbrush filaments (1) combined to a filament strand and / or wound on a filament spool (2) is applied simultaneously with the consumable-medium mixture.

6. The method according to the preceding claim, wherein filament coils (2) are used with a permeable core and / or permeable flanges or side walls.

7. The method according to any one of the preceding claims, wherein the Verbrauchsstoff- medium mixture is added to flow, so that the toothbrush filaments and / or the wear part is flowed around by the mixture during the Einbringprozesses.

8. The method according to the preceding claim, wherein the mixture is circulated in and / or by a pressure vessel (5).

9. The method according to any one of the preceding claims, wherein the Zahnbürstenfilamen- te and / or the wear part is applied in a discontinuous process in a pressure vessel (5) with the mixture.

10. The method according to any one of the preceding claims, wherein the medium for introducing the consumable in the toothbrush filaments and / or the wearing part is brought by pressure and / or temperature in the supercritical state.

11. The method according to any one of the preceding claims, wherein the consumable medium mixture is brought to a temperature between room temperature and 14O ⁰ C, preferably about 60 ⁰ C to 80 ⁰ C, brought.

12. The method according to any one of the preceding claims, wherein the consumable medium mixture with a pressure of 5 bar to 300 bar, preferably about 60 bar to 200 bar, in particular about 85 bar to 150 bar, for acting on the toothbrush filaments (1). and / or the wearing part is brought.

13. The method according to any one of the preceding claims, wherein the contact time between five minutes and five hours, preferably about 40 to 80 minutes is selected.

14. The method according to any one of the preceding claims, wherein the temperature, the pressure and / or the exposure time are dimensioned such that a penetration depth of about 0.5% to 15% of the thickness or the diameter of the toothbrush filaments and / or the corresponding Wear part is achieved.

15. The method according to any one of the preceding claims, wherein the consumable medium mixture is cooled after the expiration of the predetermined contact time and relaxed before the toothbrush filaments and / or the consumable part are removed.

16. The method according to any one of the preceding claims, wherein after the application of the consumable medium mixture, a rinse, preferably from two to five minutes, is made.

17. The method according to the preceding claim, wherein a water rinse is carried out free of acids and / or free of neutralizers.

18. The method according to any one of the preceding claims, wherein only two dipping operations are provided, namely first the dip in the consumable medium mixture and then a rinse in water.

19. The method according to any one of the preceding claims, wherein as Zahnbürstenfilamen- te (1) plastic filaments of a polymer, in particular monofilaments of polyamide, are used.

20. The method according to any one of the preceding claims, wherein a wear indicator dye is used as a consumable example, dyes from the indigotin family.

21. The method according to any one of claims 1 to 19, wherein a flavor and / or fragrance is used as a consumable.

22. The method according to any one of claims 1 to 19, being used as a consumable antibacterial substances.

23. A method for producing a toothbrush or an oral care product, wherein in the toothbrush filaments and / or in the bristle carrier and / or in a cleaning element a consumable is introduced by the method according to one of the preceding claims and then the toothbrush filaments are attached to a bristle carrier.

24. Toothbrush head having attached to a bristle carrier toothbrush filaments, wherein the bristle carrier and / or the toothbrush filaments by the method according to one of claims 1 to 22 can be produced.

25. Toothbrush with a toothbrush head according to the preceding claim.

26. Oral care product to which a dental care part is attached, which can be produced by the method according to one of claims 1 to 22.

27. Oral care product according to claim 26, characterized in that the dental care part is a toothbrush filament or a soft-elastic cleaning element or a portion of the head or the handle of a toothbrush or other oral care product.